Above are various low level weapons in Palace of the Dead. Pink is a lower level, and green is approaching powerful for the floors you are on. Bright White is appropriate for the levels where you are playing.
When you start playing in the Palace of the Dead, your weapon is pink or green and eventually, as you trigger more Silver Chests, it turns White. I could not find any place that this was carefully described.
Here’s a play guide for the Deep Dungeon aka Palace of the Dead.